Pickax.



A. R. THOMSON.

PICKAX. APPLICATION FILED Nov. 11. 1912'.

1,262,870. Patel-.19d Apr. 16, 1918.

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ALBERT REIDDJE THOMSON, OF PLANTSV ILLE, CONNECTICUT.

PICKAX.

Specication of Letters Patent. Patented Apr. ia, 11918.

Application filed November 17, 1917. Serial No. 202,544.

To all whom t may concern Be it known that l, ALBERT REDDLE THoM- son, la citizen of the United States, residing at Plantsville, in the county of Hartford and State of Connecticut, have invented certain new and useful Innarovements in Fickaxes,'

of which the following is a specification.

My invention relates to improvements in pickaxes, and particularly of the type wherein the bits are removably connected to the body portion, generally after the manner of the construction shown and described in my application filed July 29, 1916, Serial No. 112,025, and the object of my improve ment is to provide a construction permitting of manufacture of the bits by the drop forging process and at the same time obtaining, by reason of a special form of crosssection of the tapered head on the bit member and the socket in the body portion, an effective operative tit of these parts, whereby they will be positively and firmly held together, and without eXtra parts for locking the same together.

In the accompanying drawing Figure 1 is a side elevation of my improved pickaX.

Fig. 2 is a plan view of the same.

Fig. 3 is a side elevation of the body portion.

Fig. 4 is a similar view of one of the bit members.

Fig. 5 is a view on an enlarged scale, showing one side in side elevation and the other side in section.

Fig. 6 is a sectional view on the line 6-6 of Fig. 5.

Fig. 7 is a similar sectional view of a construction showing a reduced taper for the V-shaped edge of the bit member.

Fig. 8 is a view corresponding to Figs. 6 and 7 showing a steeper taper for the said V-shapcd edge, as compared with the tapers shown in the said gures.

Fig. 9 is a side elevation, in part broken away, of the construction shown in Fig. 8.

My improved pickaX comprises a body portion 10 that is provided with a handle aperture 11 in which is housed one end of the handle 12, and a pair of bit members 18 that extend outwardly from the body pora tion 10 on opposite sides of the handle 12 in the usual manner for pickaxes.

The bit member 13 comprises a pointed or specially shaped outer end le that serves as the bit proper, has a head 15 of special form at the inner end that serves as the connectlng means for connecting with the body portion 10, and intermediate the said ends has the shank 16 of generally tapered form.

The body portion 10 comprises the middle portion 17 that is provided with the aperture 11 for the handle 12 and a pair of lateral branches' 18 extending outwardly, one on each side of the said middle portion 17, one for each of the bit members 13. Each of the branches or branch arms 18 has a socket 19 of special form for receiving the head 15 and has the side walls on opposite sides provided with alining longitudinal slots 20 that open into the socket 19 for admitting a removing tool for removing the bit member 13 from the body portion 10.

Such removal of the tool is elfected in an ordinary manner by the insertion of a pry or key for engaging with the end of head 15 and driving the same out of the socket 19, which, as shown, and will be more particularly described, is longitudinally tapered, suitably to permit this to be done.

rlhus the socket 19 is what is known as a tapered socket and the head 15 is tapered to tit the same. Actually, however, the tapering of these parts is confined to the top and bottom edge portions, the side wall faces being fiat and. paralleLl Furthermore, the said top edge portion and bottom edge portion, both of the socket 19 and the head 15, besides being longitudinally tapered, as mentioned, are also of special form of cross-section.

Considering the socket 19, the same comprises border walls 23 at the sides that are flat and parallel, and appreciably separated, and the border' walls at the top and bottom edges that connect the parallel portions 23 comprise in each case an inclined wall section or face 24C on each side, of equal length and inclination, that meet at the middle 25 so as to form a V-shape for whatrmay be termed the roof portion and the base portion of the said socket 19, as distinguished from the side Wall portions 23. The body portion 10 is made of cast material, and the structure shown and described is readily made of such material by ordinary methods.

The bit member 13 is made by the drop forging process and the head portion 15 that fits in the socket 19 is longitudinally tapered i along the top and bottom edge portions, as has been mentioned', and the cross-section corresponds generally to that of the socket 19, though actually there is a positive difterence in dimensions. That is to say, the head 15 tits in the socket 19, and Without filling the same, and this condition is brought about in the following manner Considering the cross-section of the head 15, the same comprises the side faces 26 that are parallel and fiat, and opposed to the side Walls 2B of the socket 19, and at the top and bottom edge portions, at each edge portion, is a generally ii-.shaped rib 27 of suitable form to lit against the inclined tace portions 24 of the socket 19. ris these ribs 27 are positioned in the dies in forming by the drop forging process a lin is formed along the apex portion ot the same, and in trimming the same oit' a portion of the rib along the apex is preferably also trimmed ofi?, as shown at 28, thus obvia inO' the necessity of a close lit along this particular part of the structure.

Besides the difference in detail mentioned, the thickness of the head 15 is such that the same will not quite lill the space between the side Walls 23, leaving` an appreciable clearance space 29 between the opposed faces 28 and 26 on each side, Aso as to obviate the necessity ot a tit for these parts along the sidewalls.

At the same time, the head is positively and firmly held in the socket, so as to prevent twisting or lateral displacement, by reason'of the inclined bearing faces 2a, that bear against the ribs 27.

In use, l iindthat the inclined seats for the edge portions of the heads serve to :trictionally hold the head iirinly in place, so that other, special means for preventing the accidental removal of the bit member are not necessary.

incasso ing finally drawn out to the shape desired.y

The inclined faces that compose Walls of the ribs 27 are such as to be adapted to be readily formed by the drop forging process and at the same time they are adapted to serve as etifective holding means for holding the bit member in place. rTherefore, the ribs, which for the holding eifect only VWould be contined to the head portion 15, l prefer toV continue along the length of the blank, which, however, Will be obliterated from the tip end portion by the shaping of the same to the finished form.

l claim as my invention i pickax comprising in combination, a body portion having a socket that is generally tapered longitudinally and a bit member having a head that is an operative lit for the said socket, the border Walls ot the said socket comprising parallel Walls at the sides connected at the top by a roof portion and at the bottom by a base portion, and the said root' portion and base portion being each lit-shaped, and the said head beingV separated from the said parallel Walls at the sides by clearance spaces, and having at the top and bottom edge portions V-shaped ribs that fit against the said roof por-tion and base portion.

ALBERT REDDLE THOMSON.

(Genieethis patent may be obtainerller rive cents each. by aressing the Commissioner ot Eatenta, fasnington, l?. G, 

